DESCRIPTION: Inorganic filled, visible light-cured polymer matrix composite materials are alternatives to traditional Dental amalgams, because of superior aesthetics, better biocompatibility, and the lack of mercury; however, these materials have inferior strength, toughness and wear properties, which have prohibited them from completely replacing amalgams. The objective of this Phase 1 SBIR application is to utilize the fundamental properties of nanotechnology to develop a new class of Dental materials, based upon Polyhedral Oligomeric Silsequioxanes (POSS) nanocomposites. POSS nanostructures will b e substituted for the standard silica fillers currently used in composite Dental restoratives. POSS-based nanocomposite restoratives are expected to possess improved physical and mechanical properties over conventional materials, because of their nanoscopic size. The effect of POSS nanostructures upon the properties of bisGMA/TEGDMA Dental composites containing various bisGMA/TEGDMA/POSS ratios will be investigated. The physical, mechanical and handling properties of these nanocomposites will be examined and compared to current materials. By the conclusion of Phase 1, one or more POSS-based nanocomposite formulations will be selected for subsequent clinical evaluation and possible marketing. POSS nanocomposites have the potential to eliminate all of the major deficiencies that plague current Dental materials, thus permitting a quantum leap forward in the use of composite-based Dental restoratives. PROPOSED COMMERCIAL APPLICATION: Dental restoratives, dentures, and impression materials